A study cited by the Wall Street Journal (November 1, 1988) linked SLS to cataracts and nitrate absorption. The nitrate absorption occurs when the SLS becomes contaminated with NDELA (N-nitrosodiethanolamine) during processing. This contamination comes about as a result of SLS coming into contact with any number of chemicals including triethanolamine (TEA), which is commonly used in shampoos as a detergent. Put simply: SLS + TEA= NDELA (a nitrosamine and a recognized carcinogen.

"It can actually damage the outer layer of the skin, the stratum corneum, causing dryness, roughness, scaliness, fissuring, loss of flexibility and reduction of the barrier functions of normal healthy skin. The lipid dissolving action of some detergents, including SLS cause damage to the moisture retaining ability of the cellular level resulting in water loss and loss of water- binding ability" (Cosmetic Science, C. Prottey, 1978)

Sodium lauryl sulfate, a surface-active agent and a common surfactant used in shampoos, was found to increase the absorption of certain chemicals. Simply put, SLS in your shampoo could be increasing the rate of skin absorption of other chemicals in your shampoo and conditioner which may include preservatives, fragrances and color additives. (Cosmetic and the Skin, F.V. Wells, Reinhold Publishing Corporation, New York, 1964)

SLS has been blamed for many cases of premature hair loss in both men and women. It takes hair longer to grow when it has been affected by SLS. Studies are ongoing in this area. SLS is cheap and available and cost is definitely a factor when manufacturers are deciding on their formulations. The irony is that we as consumers rarely see any of this saving and pay high prices for products that contain the same cheap ingredients as a lower priced product that doesn't have the benefit of a well-known name and a huge advertising budget. There are safer products on the market. There are safer alternatives to SLS but they can cost up to ten times more than SLS. One manufacturer said "I know it's not a good ingredient, but everyone uses it."

Did you know that many companies put formaldehyde in their shampoos? Do you really want to be embalming your hair? Formaldehyde is not only an inexpensive preservative and disinfectant; it's also a suspected cancer-causing toxin. In 1983, researchers from the Division of Cancer Cause and Prevention of the National Cancer Institute recommended that it be further investigated since there is a suspected link to some cancers. It was found to ca...